1. Field of the Invention
The field of invention relates to the production of butanol. More specifically, the field relates to the production of butanol via butene hydration.
2. Description of the Related Art
Butanol is an effective alternative to traditional oxygenates and fuel-stock expanders, which includes methyl tert-butyl ether and ethanol. Butanol not only contributes octane-rating enhancement but also supplies incorporated oxygen into the fuel mix. Mixed or blended butanols are also relatively inexpensive.
The primary means for producing butanol, especially mixed butanols, is through a butene hydration process. Known butene hydration processes include liquid-liquid biphasic systems. Butenes and water are immiscible in one another at low relative concentrations (both butene-in-water and water-in-butene) systems. Elevated operating conditions do not alleviate the immiscibility. The immiscibility of the reactants is one reason for the known low single-pass conversion rate.
In addition, the immiscibility also affects the distribution of the hydration catalyst. Typical hydration catalysts prefer either the aqueous phase or the hydrocarbon phase—usually not both. This poor distribution of hydration catalyst does not foster catalytic reactions throughout the biphasic system but rather predominantly in only one phase.
A need therefore exists to improve the single-pass conversion yield of butene into butanol in butene hydration systems and processes.